Nonspecular reflection, resonance scattering and radiation of sound by elastic bodies in water

Results of studies of sound reflection by plates and shells immersed in water are given. The are incidence angles of sound waves upon plates or shells, under which strong reflection backwards, i.e. nonspecular reflection, is observed. Physical nature of nonspecular reflection is discussed and its theory is given. It is demonstrated that nonspecular reflection is accompanied by the effect of spatial-frequency resonance. It is revealed that resonance scattering and radiation of sound by shells immersed in water is connected with the effect of spatial frequency resonance. The discussed effects can play the dominant role in formation of underwater acoustic fields.